In an information recording medium of a recording type, such as a CD-R (Compact Disc-Recordable), a DVD-R, a DVD-RW, a DVD+R, and a BD-RE (Blu-ray Disc Rewritable), for example, laser light for recording is focused or condensed on at least one of recording layers laminated or pasted on a substrate, to thereby record information into the recording layer in an irreversible change recording method by heat or in a rewritable method. Alternatively, management information is recorded in advance in a management information recording area or the like, for example, which is provided in the recording layer. The management information herein is various information for managing the information recording medium, such as information about recording features, like an optimum recording power or the like, and attribute information for specifying the type of the medium. More specifically, in the DVD-R, the management information is recorded in advance by the laser light. Alternatively, in the DVD-RW, the management information is recorded in advance by forming embossed pits on the inner circumferential side.
In particular, in the BD-RE in which recording or reproduction is performed by the laser light with a relatively short wavelength, such as a BD with a wavelength of 405 nm, the management information is recorded in advance by a groove track in a modulation method different from that in a user data area. In addition, the management information is the only unique information which could know the characteristics of the optical disc and it is important. Thus, there is also proposed a method of relatively increasing a track pitch to prevent a reduction in reproduction quality, caused by an influence from an adjacent track, i.e. crosstalk, such that the management information can be read, certainly and properly, by an information recording/reproducing apparatus, such as a drive. In particular, in the BD-RE, its spot diameter is relatively smaller than the spot diameter of the DVD or the like, for example. Thus, relatively increasing the track pitch as described above is effective in terms of improving the reproduction quality.    Patent document 1: Japanese Patent Application Laid Open NO. 2003-346384